1. Field of the Invention
The present invention relates to an image forming apparatus including a nip portion for a recording material, which is formed with a first roller member and a second roller member directly or via a belt member.
2. Description of the Related Art
An image forming apparatus, which is widely used, is configured such that a toner image formed on an image bearing member is transferred onto a recording material directly or via an intermediate transfer member, and the recording material bearing the transferred toner image is heated and pressed by a fixing device as an example of an image heating device to fix the image to the recording material. The image forming apparatus includes nip portions for a recording material, which are formed with a first roller member and a second roller member directly or via a belt member in a transfer portion and a fixing device for the recording material carrying a toner image. The image forming apparatus is required to ensure a large working space for removing a jammed recording material by releasing the nip portions when a jam of recording material occurs.
Japanese Patent Application Laid-Open No. 2009-251135 discusses an image forming apparatus including a door member, which is on a rotation shaft horizontally arranged in a lower area thereof, attached on a side surface so that an upper portion of the door member is tilted to open and close. A supporting member on which a secondary transfer roller is rotatably attached is opened and closed parallel to the door member on a rotation shaft arranged in a lower area of the secondary transfer portion of the image forming apparatus. Accompanying a closing movement of the door member, the supporting member of the secondary transfer roller is pushed by the door member to rotate toward the intermediate transfer belt, and thereby a secondary transfer portion is formed between the secondary transfer counter roller and the intermediate transfer belt. Accompanying an opening movement of the door member, the supporting member of the secondary transfer roller rotates outward to release a nip portion between the secondary transfer roller and the intermediate transfer belt, and thereby a working space for removing a jammed recording material is ensured.
According to the image forming apparatus discussed in Japanese Patent Application Laid-Open No. 2009-251135, since the supporting member of the secondary transfer roller is pivotally supported on the image forming apparatus side using a fixed rotation shaft, a working space larger than a rotation radius of the secondary transfer roller provided by the supporting member is not ensured between the secondary transfer roller and the intermediate transfer belt. The supporting member of the secondary transfer roller interferes with access to a working space between the secondary transfer roller and the intermediate transfer belt.